Module 07
Slides 31–35 | From targeting anatomical structures to understanding the networks and pathways actually engaged by stimulation
Original lecture slides 31–35 · Module 07 / 10
“Where the lead is placed is only the beginning. The therapeutic question is which neural elements and networks are actually being modulated.”
From coordinates to circuits
Modern DBS targeting is moving from coordinates and nuclei toward patient-specific circuits, pathways and stimulation fields — as a complement to, not a replacement for, conventional anatomical targeting.
Learning objectives
Original lecture slides
The slides below are reproduced exactly as delivered. Everything outside the slide panel is added study material.
Slide 31
Slide 32
Slide 33
Slide 34
Slide 35
Keyboard: ← previous slide · → next slide · O original slide · S study mode
Expanded study material
Supplementary material written around the immutable original slides.
Interactive principle
Two ways of describing the same implanted lead.
The classical question: where is the target, and which coordinate reaches it? The lead is placed in a nucleus and the nucleus is treated as the therapeutic unit.
The two approaches are complementary. Network reasoning does not reduce the importance of millimetric lead placement — it explains why it matters.
Interactive principle
Seven steps, each of which can be the weakest link.
Acquisition protocol, diffusion scheme, distortion and motion handling set the ceiling for everything downstream.
Connectomic prediction must be validated against clinical outcome.
Critical thinking
A beautiful connectivity map is not automatically a validated therapeutic target.
Interactive principle
Schematic only — never a reproduction of published patient data.
Schematic · model-derived response map
Overlapping stimulation fields from many patients, weighted by outcome, produce a region of higher response association: the putative sweet spot. The underlying biology may be a pathway or network rather than the region itself.
This is a schematic, not patient data and not a published map. Discovery is not validation; association is not causation.
Interactive principle
Illustrative model of how amplitude and steering change a modelled field.
Illustrative model — not patient data
A larger modelled field is not automatically more therapy: it increases the chance of engaging both the intended pathway and adjacent sensitive structures. Steering redistributes the modelled field around the lead without moving it.
In this illustration the modelled field remains away from the adjacent capsular territory.
These relationships are model-dependent and not simple linear rules. VTA overlap does not guarantee benefit, and absence of overlap does not prove absence of effect.
This connects directly to Slide 26 — Directional DBS and Slide 27 — Therapeutic Window.
Decision framework
Work down the questions; a negative answer is an acceptable endpoint.
Anatomy + phenotype + pathway + field + clinical evidence
Academic caution
The surgeon must still understand phenotype, target anatomy, trajectory safety, lead placement, programming, adverse-effect anatomy and disease progression — and must understand the limitations of the imaging model being used.
Cross-links
Each link opens the related original slide elsewhere in the curriculum.
Future / research direction
No definitive answer is offered — this is a debate to hold with your unit.
From “where is the lead?” to “what is the lead modulating?”
ANATOMY + PATHWAY + NETWORK + STIMULATION FIELD + PHENOTYPE = PRECISION NEUROMODULATION
Deep study material
DBS produces effects that extend beyond simple local neuronal inhibition.
Network-level and fibre-mediated mechanisms are strongly supported by experimental and imaging literature.
Connectomic approaches are increasingly supported for understanding symptom-specific circuits and retrospective outcome prediction. Prospective clinical validation and standardized pipelines are still needed before conventional targeting paradigms are displaced.
Valuable for research, pathway visualization and increasingly sophisticated planning. Clinical utility varies by target, acquisition protocol, reconstruction method and institutional expertise; it is not mandatory for all DBS procedures.
Established research and clinical programming concepts. The VTA remains a computational approximation and should not be read as a direct measurement of neuronal activation.
Anatomy
Expanded study material for this section is written once the original slides for this module are supplied.
Surgical principles
Expanded study material for this section is written once the original slides for this module are supplied.
Physiology
Expanded study material for this section is written once the original slides for this module are supplied.
Imaging
Expanded study material for this section is written once the original slides for this module are supplied.
Programming
Expanded study material for this section is written once the original slides for this module are supplied.
Image placeholders
Each placeholder states the image type, what is required, why it teaches and where a legitimate source should come from. No clinical image is fabricated.
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MODULE 07 CONNECTOMIC DBS WORKFLOW — INSERT AUTHENTIC IMAGE
Real clinical image required
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MODULE 07 LEAD RECONSTRUCTION + VTA ATLAS FIGURE — INSERT AUTHENTIC IMAGE
Real clinical image required
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Nuclei to networks
02
Connectomic targeting
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Sweet spot
04
Tractography
05
Volume of tissue activated
THE TARGET IS NOT ONLY WHERE THE LEAD IS. THE TARGET IS WHAT THE STIMULATION ENGAGES.
Clinical pearls
Common errors
Take-home message
References
“PRECISION DBS IS NOT SIMPLY MORE PRECISE COORDINATES. IT IS BETTER UNDERSTANDING OF WHERE THE LEAD IS, WHAT FIELD IT CREATES, WHICH FIBRES IT ENGAGES, WHICH NETWORK IT MODULATES, AND WHICH SYMPTOM WE ARE TRYING TO CHANGE.”
